Consequences of the introduction of cereal - grain legume intercrops in the supply chain. Analysis from the perspective of farmers and cooperatives

Intercropping (the simultaneous growth of 2 or more species in the same field) is one way to solve some difficulties that organic supply chain has to face. The aim of this article is to assess the consequences and the compatibility with intercrops at 2 levels: i) cropping systems of 18 farmers from north of France and ii) the logistics ofagricultural cooperatives which collect durum wheat in Midi-Pyrenees altogether with two cooperatives that already had experimented intercrops (Terrena and AgriBioUnion).The conclusions of our work is that intercrops seem a priori compatible with farmers’ cropping systems and with the presentlogistic organization of cooperatives but the main difficulty remains the feasibility and the cost in sorting out grains. Constraints and benefits of intercrops must then be analyzed more precisely at each level of the supply chain in order to collectively develop solutions

Grain legume–cereal intercropping systems

Chapitre 11Grain legume–cereal intercropping system

Améliorer la qualité technologique, nutritionnelle et sanitaire du bléiologique. Principaux leviers agronomiques et technologiques

Communication lors du colloque "DinABio 2013", 13 et 14 novembre 2013 à Tours (Fance)The organic bread wheat market has been diversified over time through the emergence of different sale channels. Processors require organic bread wheat of higher quality and safety in order to meet the consumers’ demand. The overall objective of the AGTEC-Org project was to identify agronomical and technological ways to improve the performance of organic wheat and flour. The findings would contribute to enhanced baking quality and nutritional value of organic flour, as well as prevention of mycotoxin contamination. The project involved 9 research centers or universities from 5 European countries for a total budget of about 1.5 million €. More than 400 experimental treatments were analyzed from 23 agronomic trials and 4 lab-experiments on food technology. Choice of cultivar is an efficient way to obtain higher grain quality. Intercropping legumes (grain or forage) improves weed control and N availability for wheat crop or succeeding crop. Green manure can be an effective alternative to farmyard manure. Fertilization with organic fertilizers improves yield and quality when water is available. Reduced tillage affects soil fertility and wheat yield but has little effects on grain quality. Milling process strongly influences flour characteristics. Stone milling improves the nutritive value and flour characteristics remain very stable independently of the milling yield. However, stone milling slightly raises DON levels. Characteristics of flour produced by means of roller milling appear very dependent on milling yield, instead. Increasing milling yield with the aim of enriching nutritional quality has a detrimental effect on either safety (DON) or bread-making quality (bread volume). Debranning before milling has a very positive impact on flour safety by reducing its DON content by 50 %.Les acteurs de la filière blé biologique panifiable font face à divers enjeux complémentaires voire parfois contradictoires. Les agriculteurs et transformateurs souhaitent augmenter les niveaux de production tout en satisfaisant prioritairement les attentes des consommateurs pour une alimentation de meilleure qualité nutritionnelle et sanitaire, plus durable et plus respectueuse de l’environnement. Le projet européen AGTEC-Org a eu pour objectif d’identifier les leviers agronomiques et technologiques permettant d’améliorer conjointement la productivité et la qualité des blés et des farines biologiques. Il a réuni agronomes, technologues et économistes issus de 9 centres de recherche et universités européennes pour un budget total de 1,5 M€. Plus de 400 traitements expérimentaux ont été analysés à partir de 23 expérimentations agronomiques et 4 expérimentations technologiques. Le choix de la variété est un moyen efficace pour obtenir une qualité de grain supérieure. L’insertion de légumineuses (grain ou fourrage) dans le blé améliore la compétition avec les adventices et la nutrition azotée du blé et/ou de la culture de printemps suivante. L’utilisation régulière d’engrais vert peut être une alternative pour compenser l’absence de fumiers sur l’exploitation. La fertilisation organique améliore le rendement et la qualité des blés lorsque la nutrition hydrique est assurée. La suppression du labour peut affecter la fertilité du sol et le rendement du blé alors qu’elle n’intervient pas sur la qualité du grain. Le mode de broyage (meule de pierre vs cylindres) influence fortement les caractéristiques technologiques, la sécurité sanitaire et la valeur nutritionnelle de la farine. Le broyage sur meule améliore la composition nutritionnelle mais augmente aussi la présence de certains contaminants. Les caractéristiques de la farine broyée sur meule de pierre sont moins influencées par le rendement en mouture. Au contraire, les caractéristiques de la farine obtenue par cylindre apparaissent très dépendantes du rendement en mouture. Augmenter le rendement en farine dans l’objectif d’enrichir la qualité nutritionnelle réduit aussi bien la sécurité sanitaire (DON) que la qualité boulangère (volume du pain). Le décorticage des grains avant broyage diminue les risques sanitaires en réduisant le taux de mycotoxines (DON) de 50%

Pea–wheat intercrops in low-input conditions combine high economic performances and low environmental impacts

Intensive agriculture ensures high yields but can cause serious environmental damages. The optimal use of soil and atmospheric sources of nitrogen in cereal–legume mixtures may allow farmers to maintain high production levels and good quality with low external N inputs, and could potentially decrease environmental impacts, particularly through a more efficient energy use. These potential advantages are presented in an overall assessment of cereal–legume systems, accounting for the agronomic, environmental, energetic, and economic performances. Based on a low-input experimental field network including 16 site-years, we found that yields of pea–wheat intercrops (about 4.5 Mg ha−1 whatever the amount of applied fertiliser) were higher than sole pea and close to conventionally managed wheat yields (5.4 Mg ha−1 on average), the intercrop requiring less than half of the nitrogen fertiliser per ton of grain compared to the sole wheat. The land equivalent ratio and a statistical analysis based on the Price\u27s equation showed that the crop mixture was more efficient than sole crops particularly under unfertilised situations. The estimated amount of energy consumed per ton of harvested grains was two to three times higher with conventionally managed wheat than with pea–wheat mixtures (fertilised or not). The intercrops allowed (i) maintaining wheat grain protein concentration and gross margin compared to wheat sole crop and (ii) increased the contribution of N2 fixation to total N accumulation of pea crop in the mixture compared to pea sole crop. They also led to a reduction of (i) pesticide use compared to sole crops and (ii) soil mineral nitrogen after harvest compared to pea sole crop. Our results demonstrate that pea–wheat intercropping is a promising way to produce cereal grains in an efficient, economically sustainable and environmentally friendly way

The competitive ability of pea-barley intercrops against weeds and the interactions with crop productivity and soil N availability

Grain legumes, such as peas (Pisum sativum L.), are known to be weak competitors against weeds when grown as the sole crop. In this study, the weed-suppression effect of pea–barley (Hordeum vulgare L.)intercropping compared to the respective sole crops was examined in organic field experiments across Western Europe (i.e., Denmark, the United Kingdom, France, Germany and Italy). Spring pea (P) and barley(B) were sown either as the sole crop, at the recommended plant density (P100 and B100, respectively), or in replacement (P50B50) or additive (P100B50)intercropping designs for three seasons (2003–2005). The weed biomass was three times higher under the pea sole crops than under both the intercrops and barley sole crops at maturity. The inclusion of joint experiments in several countries and various growing conditions showed that intercrops maintain a highly asymmetric competition over weeds, regardless of the particular weed infestation (species and productivity), the crop biomass or the soil nitrogen availability. The intercropping weed suppression was highly resilient, whereas the weed suppression in pea sole crops was lower and more variable. The pea–barley intercrops exhibited high levels of weed suppression, even with a low percentage of barley in the total biomass. Despite a reduced leaf area in the case of a low soil N availability, the barley sole crops and intercrops displayed high weed suppression, probably because of their strong competitive capability to absorb soil N. Higher soil N availabilities entailed increased leaf areas and competitive ability for light, which contributed to the overall competitive ability against weeds for all of the treatments. The contribution of the weeds in the total dry matter and soil N acquisition was higher in the pea sole crop than in the other treatments, in spite of the higher leaf areas in the pea crops

Modelling competition for below-ground resources and light within a winter pea (Pisum sativum L.)–wheat (Triticum aestivum L.) intercrop (Azodyn-InterCrop): towards a decision making oriented-tool

Grain legume-cereal intercrops allow a gain of productivity grown along the growth cycle on the same piece of land under low input (of which nitrogen (N) fertilizers) levels. This is partly due to a better use of soil nitrogen (larger available soil N per plant for cereal N uptake and an increased contribution of N fixation for pea nutrition) under combinations (species and crop management systems) fully optimized within a given soil and climate environment. Modeling is a powerful tool to explore a wide range of combinations. It can be further used as a decision making oriented-tool provided below-ground resources and light sharing is satisfactorily simulated. Our work aimed at designing a new dynamic intercrop growth model (Azodyn Inter-Crop (IC)) based upon Azodyn for wheat and Afisol for pea. Nitrogen and water partitioning between species is firstly driven by nitrogen and water demand of each species. When intercrop demand is larger than soil supply then water and N acquisition is limited by root exploration, soil nutrient supply and N taken up by the companion species as it concurrently depletes available below-ground resources. The ‘functional’ root layer concept allows to account for advantage towards species with a faster root penetration rate. Leaf area expansion is driven by daily satisfaction of N demand, itself computed through an adapted version of N dilution curve to intercrop growth. Light sharing depends on leaf area index (LAI) growth and leaf properties (reflectance, leaf angle) of each species. Model outputs show Azodyn-IC can satisfactorily simulate N taken up, LAI, light interception efficiency and crop growth of each sole- and intercropped species along the growth cycle leading to realistic yields for the applied N fertilizer rates. It also emphasizes competition for light and below-ground resources within intercrops is tightly and dynamically linked within intercrop

Déterminants écologiques et physiologiques de la productivité et de la stabilité des associations graminées-légumineuses

Grasses (Poaceae) and legumes (Fabaceae) represent the two most important botanical families for food and feed production. They are frequently grown as mixtures (i.e. intercropped simultaneously in the same field) to take advantage of their different ecological and agronomical requirements as well as of their nutritional complementarities. Yield, quality and environmental efficiency of the grass-legume mixtures directly depend on the contribution of the legume in the mixture at harvest. The control of mixture change however remains a challenging task. This article aims at examining how the interactions between plant traits, environment (and more particularly resource availability) and crop management influence productivity and species composition of grass-legume and cereal-grain legume mixtures of temperate origin. The role of developmental processes and resource-based interactions (competition and facilitation processes) in the occurrence of plant complementarities are more particularly discussed. In the last section, the effects of different management practices on mixtures are presented with particular references to different cropping systems (forage, grain, and bio-fuel production).Les graminées (Poaceae) et les légumineuses (Fabaceae) constituent les deux familles botaniques les plus importantes pour l’agriculture. Leur culture en association (simultanément sur la même parcelle) est un usage ancien qui permet de valoriser les différences écologiques, agronomiques et nutritionnelles des deux familles. Les performances de ces cultures associées en termes de production, de qualité et de bénéfices environnementaux sont étroitement liées à la capacité à maîtriser la proportion de graminées et de légumineuses dans le mélange. L’objectif de cet article est d’examiner comment les interactions entre les caractéristiques propres de chacune des composantes, le milieu (et particulièrement la disponibilité en ressources) et les pratiques culturales affectent la productivité et l’équilibre entre espèces au sein d’associations de graminées et légumineuses d’origine tempérée, annuelles ou pérennes. L’importance des relations de compétition et de facilitation dans l’émergence de complémentarités et les principaux moyens d’action pour les orienter sont plus particulièrement discutés

Produire des légumineuses à graines au moyen de l’association avec une céréale : cas de la lentille et du lupin blanc d’hiver

Grain legumes provide numerous nutritional, agronomic and environmental benefits and are at the core of the sustainability challenges of agricultural systems. Yet, grain legumes are hardly cultivated in Europe, not least because of strong agronomic constraints that reduce their yields and increase yield instability. Two PhD theses were performed to 1) assess the potential of intercropping cereals (wheat, triticale) with grain legumes (lentil and winter white lupin) to reduce the impacts of agronomic constraints on legume production; 2) better understand the functioning of these intercrops to improve their agronomic and economic performances. Intercropping legumes with a low density of cereal increased total grain yield in almost all tested situations compared to sole crops. The better global performance of intercrops was mainly due to a higher acquisition of light and nitrogen resources resulting from complementarities between species within the intercrops. Moreover, the presence of the cereal reduced weed biomass and lentil lodging. Intercropping legumes with cereals is thus a suitable agricultural practice to foster grain legume production in Europe